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roassal pixel rendering

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Peter Uhnak

roassal pixel rendering

Hi,

I've been experiencing weird behavior with pixel rendering...

basically one pixel lines will get blurred for some reason even though there is no half-pixel overlapping.

Here is a test code (screenshots attached below).

Without the labels the left box will be blurred while the right is better (even though it still has slight shadow); when I add labels however their behavior will switch.

What I would expect is to have nice sharp lines all the time.

Is this Athens issue? Roassal? Pharo?

Its ugly both on Linux and Windows.

====================================

| view box1 box2 |

view := RTView new.

box1 := RTBox new width: 50; height: 51; fillColor: Color transparent; borderColor: Color black; elementOn: '50@51'.

view add: box1.

box2 := RTBox new width: 51; height: 50; fillColor: Color transparent; borderColor: Color black; elementOn: '51@50'.

view add: box2.

"box1 @ RTLabelled.

box2 @ RTLabelled."

box1 translateTo: -50 @ 0.

box2 translateTo: 50 @ 0.

view open

====================================

Peter

without labels.png (1K) Download Attachment

with labels.png (4K) Download Attachment

basilmir

Re: roassal pixel rendering

What is your host system?

If you're on a mac is it Retina?

If you're on windows, what dpi setting are you using?

Pe 3 mar. 2015, la 00:31, Peter Uhnák <[hidden email]> a scris:

> Hi,
>
> I've been experiencing weird behavior with pixel rendering...
>
> basically one pixel lines will get blurred for some reason even though there is no half-pixel overlapping.
>
> Here is a test code (screenshots attached below).
> Without the labels the left box will be blurred while the right is better (even though it still has slight shadow); when I add labels however their behavior will switch.
>
> What I would expect is to have nice sharp lines all the time.
> Is this Athens issue? Roassal? Pharo?
> Its ugly both on Linux and Windows.
>
> ====================================
> | view box1 box2 |
> view := RTView new.
> box1 := RTBox new width: 50; height: 51; fillColor: Color transparent; borderColor: Color black; elementOn: '50@51'.
> view add: box1.
> box2 := RTBox new width: 51; height: 50; fillColor: Color transparent; borderColor: Color black; elementOn: '51@50'.
> view add: box2.
>
> "box1 @ RTLabelled.
> box2 @ RTLabelled."
>
> box1 translateTo: -50 @ 0.
> box2 translateTo: 50 @ 0.
>
> view open
> ====================================
>
> Peter
>
> <without labels.png>
> <with labels.png>

Peter Uhnak

Re: roassal pixel rendering

On Tue, Mar 3, 2015 at 9:15 AM, Mircea S. <[hidden email]> wrote:

What is your host system?

If you're on a mac is it Retina?

If you're on windows, what dpi setting are you using?

As I've mentioned, it is both on Linux and Windows (I don't have a mac so I can't test that).

My Linux laptop LCD has 96dpi, and external screen probably higher (I'll check in the evening).

The Windows was another machine, also 96dpi.

However I don't see how that could be DPI related considering with the "correct" size it is rendered correctly.

Peter

Pe 3 mar. 2015, la 00:31, Peter Uhnák <[hidden email]> a scris:

> Hi,
>
> I've been experiencing weird behavior with pixel rendering...
>
> basically one pixel lines will get blurred for some reason even though there is no half-pixel overlapping.
>
> Here is a test code (screenshots attached below).
> Without the labels the left box will be blurred while the right is better (even though it still has slight shadow); when I add labels however their behavior will switch.
>
> What I would expect is to have nice sharp lines all the time.
> Is this Athens issue? Roassal? Pharo?
> Its ugly both on Linux and Windows.
>
> ====================================
> | view box1 box2 |
> view := RTView new.
> box1 := RTBox new width: 50; height: 51; fillColor: Color transparent; borderColor: Color black; elementOn: '50@51'.
> view add: box1.
> box2 := RTBox new width: 51; height: 50; fillColor: Color transparent; borderColor: Color black; elementOn: '51@50'.
> view add: box2.
>
> "box1 @ RTLabelled.
> box2 @ RTLabelled."
>
> box1 translateTo: -50 @ 0.
> box2 translateTo: 50 @ 0.
>
> view open
> ====================================
>
> Peter
>

> <without labels.png>
> <with labels.png>

HilaireFernandes

Re: roassal pixel rendering

In reply to this post by Peter Uhnak

Le 02/03/2015 23:31, Peter Uhnák a écrit :
>
> basically one pixel lines will get blurred for some reason even though
> there is no half-pixel overlapping.
>

I noted the same visual artefact on Dr. Geo with perfectly horizontal 1
pixel width/horizontal line (enclosed zoomed screenshot)

Hilaire

--
Dr. Geo - http://drgeo.eu
iStoa - http://istoa.drgeo.eu

DrGeo-blur.png (8K) Download Attachment

http://drgeo.eu

Nicolai Hess

Re: roassal pixel rendering

2015-03-03 15:44 GMT+01:00 Hilaire <[hidden email]>:

Le 02/03/2015 23:31, Peter Uhnák a écrit :
>
> basically one pixel lines will get blurred for some reason even though
> there is no half-pixel overlapping.
>

I noted the same visual artefact on Dr. Geo with perfectly horizontal 1
pixel width/horizontal line (enclosed zoomed screenshot)

with cairo, coordinates are between pixels

-> http://cairographics.org/FAQ/#sharp_lines

Hilaire

--
Dr. Geo - http://drgeo.eu
iStoa - http://istoa.drgeo.eu

Peter Uhnak

Re: roassal pixel rendering

with cairo, coordinates are between pixels

-> http://cairographics.org/FAQ/#sharp_lines

Aha! Thank you.

Now the question is how this could be solved. One of their suggestions is use even-integer width, but that from principle wouldn't be true, since it still overlaps by half-a-pixel (so one full and two 1/2 pixels). So the other option is to apply transformation matrix to the whole visualization? So much work for a sharp line. :( And considering that it seems to be blurred in one axis differently than the other... I'll play some more with it.

Pete

abergel

Re: roassal pixel rendering

Hi Peter!

I was able to reproduce the problem you describe on Mac.
Indeed, it would be great to have a solution for this.

Thanks for looking into this.

Cheers,
Alexandre

> On Mar 3, 2015, at 10:37 AM, Peter Uhnák <[hidden email]> wrote:
>
> with cairo, coordinates are between pixels
>
> -> http://cairographics.org/FAQ/#sharp_lines
>
> Aha! Thank you.
>
> Now the question is how this could be solved. One of their suggestions is use even-integer width, but that from principle wouldn't be true, since it still overlaps by half-a-pixel (so one full and two 1/2 pixels). So the other option is to apply transformation matrix to the whole visualization? So much work for a sharp line. :( And considering that it seems to be blurred in one axis differently than the other... I'll play some more with it.
>
> Pete
>

--
_,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:
Alexandre Bergel http://www.bergel.eu
^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.

abergel

Re: roassal pixel rendering

In reply to this post by Peter Uhnak

Added this issue here:
https://code.google.com/p/moose-technology/issues/detail?id=1109

Cheers,
Alexandre

> On Mar 2, 2015, at 5:31 PM, Peter Uhnák <[hidden email]> wrote:
>
> Hi,
>
> I've been experiencing weird behavior with pixel rendering...
>
> basically one pixel lines will get blurred for some reason even though there is no half-pixel overlapping.
>
> Here is a test code (screenshots attached below).
> Without the labels the left box will be blurred while the right is better (even though it still has slight shadow); when I add labels however their behavior will switch.
>
> What I would expect is to have nice sharp lines all the time.
> Is this Athens issue? Roassal? Pharo?
> Its ugly both on Linux and Windows.
>
> ====================================
> | view box1 box2 |
> view := RTView new.
> box1 := RTBox new width: 50; height: 51; fillColor: Color transparent; borderColor: Color black; elementOn: '50@51'.
> view add: box1.
> box2 := RTBox new width: 51; height: 50; fillColor: Color transparent; borderColor: Color black; elementOn: '51@50'.
> view add: box2.
>
> "box1 @ RTLabelled.
> box2 @ RTLabelled."
>
> box1 translateTo: -50 @ 0.
> box2 translateTo: 50 @ 0.
>
> view open
> ====================================
>
> Peter
>
> <without labels.png><with labels.png>

--
_,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:
Alexandre Bergel http://www.bergel.eu
^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.

HilaireFernandes

Re: roassal pixel rendering

In reply to this post by Nicolai Hess

Le 03/03/2015 16:22, Nicolai Hess a écrit :
> with cairo, coordinates are between pixels
>
> -> http://cairographics.org/FAQ/#sharp_lines
>
Yeah, I guess something like that.

Thanks

Hilaire

--
Dr. Geo - http://drgeo.eu
iStoa - http://istoa.drgeo.eu

http://drgeo.eu